DS402 Axis Cyclic Position/Velocity Issue


i would like to share an issue i have with a DS402 compatible LinMot Drive. The Motor and Drive work fine and can be controlled via the LinMot Talk Software. The Drive is also connected to the PLC successfully via PL and the axis can be homed via MpAxisBasic using mapp Cockpit.

However, when I send Motion Commands like “Move Additive” oder “Jog” through the PLC, the motor movement is not smooth and quiet like when motion commands are generated directly from the LinMot Drive. The Motor vibrates strongly when in motion. LinMot Support technicians couldn’t find any issue with the drive but noticed, that the Commands sent from the PLC don’t seem to be correct. The “Demand Velocity” Value changes from 0 to the desired target value every few miliseconds (not quite bus cycle time?). This is the reason that the motor can’t perfom a smooth motion but rather small motion steps, thus generating vibration and noise. The technician told me, that he didn’t observe this kind of behavior with PLCs of other brands. I did follow LinMot’s advices to validate my PL settings but couldn’t find anything to be wrongly configured.

Did someone come across a similar Problem?
(I recorded the movement with the integrated LinMot oscilloscope but can’t yet upload to this forum)

Solved the issue, task cycle time was 10ms, PL 2ms. Both need to be the same.


cool thanks for feedback :slight_smile: